Sewing machine



Oct. 8, 1935. G. A. FLECKENSTEIN SEWING MACHINE 7 Filed Sept. 6, 1934Geowe Flccknaiein rained a. c, 1935 2,016,938

UNITED STATES PATENT OFFICE SEWING MACHINE George A. Fleckenstein,Stratford, Conn, assignor to The Singer Manufacturing Company,Elizabeth, N. J., a corporation of New Jersey Application September 6,1934, Serial No. 742,918

12 Claims. (Cl. '112-235) This invention relates to improvements inseweluding a feed-dog 9, carried by a feed-bar l ing machines and. hasfor its primary object to and projected through suitable feed-slots inthe provide for efficiently advancing work past the throat-plate 2. Anysuitable mechanism may be stitch-forming mechanism of a sewing machineemployed for impartin h ual rising and fallhaving a four-motion feedyieldingly opposed by ing, and the work-advancing and return move "'5 apresser-device. ments to the feed-dog.

More specifically, the invention has for its obe d y pp to the feed-(g 9is a P ject to minimize friction in the bearing or bear- 0 ll de a ab ySecured t t e lower end of ings of a presser-foot carrying bar shiftedenda vertically disposed presser-bar l2 journaled for V 10 wise d t u tth tio of a workdendwise movement in-a fixed bearing bushing i31 Vancingfeed mechanism operated at high speed. The bu h n it i suitably securedi an p r ure With the above and other objects in view, the in the lowerwall of the bracket-arm head 3 invention comprises the devices,combinations to extend within said head and to dep thereand arrangementsof parts hereinafter described from a substantial distance. Preferably,the

in connection with the acompanying drawing bushing l3 d p m e ead 3 hemaxiwhich illustrates several embodiments of the inm extent pe therequisite Vertical Vention, from which the several features of the m vnt f th Presser-foot H, to thereby ininvention and the advantagesattained thereby crease the effectiveness of ,said bearing in pwill bereadily understood by those skilled in s i th P s r against the sidethrust th t 1 thereof occasioned by the engagement of the 20 In theaccompanying drawing, Fig. 1 is a front P o by the feed-(10g during Wk-adend elevation, partly in section, of a sewing ma- Vaneihg movementsof the letter at high p d chine containing one embodiment of the presentp a o invention. Fig. 2 is an enlarged sectional View t its pp end t DSlidingly of the carrying bracket oi the thrust-absorbters a cappedbearing-bu l4 di stabh 25 ing roller, the section being takensubstantially threaded in h pp r W l f h br k -arm on the line 2-2 ofFi 1. Fi 3 is an enlarged h ad 3 and h ld s ur d in ad ust d p siti n ybottom plan view of the roller-carrying bracket a t-S rew 3- e Dr -bar 2has a bore shown in Fig. l as secured upon the pressert pr f a yextending th maj r p ti n f th bar bearing bushing, the presser-barbeing shown ngth of the bar and from the upp end therein ection, Fig 4is a, fragmentary front, end Of, to receive a C011 spring 51 andanabutment elevation of the bracket-arm head of a sewing Ted The Tod s np d between the machine containing a modified friction-reducing l 0f thebushing 14 and the 0011 Spring device for the presser-bar. Fig. 5 is arear side whereby the P s ai s y i s y u d downelevation of themodification shown in Fig. 4. W rdIy toward the work-support under anad- 35 Figs. 6 and 7 represent front end and rear side Li a e. p s

views in elevation of another modification of Embracing theDresser-103118 e usual lifterth present im rove e t, sleeve iii, ofwhich the upper end engages a col- Referring to the drawing, a sewingmachi lar 2E clamped upon the presser-bar and the lower containing thepresent improvement is illusd ar i s a a ally x nd n a m en ag trated ashaving a cloth-plate I, provided with able by the usual h ndlifter-lever 22 pivotally the usual throat-plate 2, and a bracket-armovermounted up e br c et-arm head.

hanging the cloth-plate, which brack tt r In the form of the improvementillustrated in minates at its free end in a hollow head 3. Figs- 1 t0 3inclusive of the d w there s Journaled for vertical reciprocation in themp y a screw 3 p the p ion of th bracket-arm head 3 is a needle-bar 4,carrying fixed bushing it below the head 3, a split collar at its lowerend a needle 5 and connected by a 25 having depending p dbracket-members 25 link 6 to a crank-disk 1 carried by a rotary disposedat the rear side of the presser-bar I2.

needle-reciprocating shaft 8. The needle 5 co- Mounted between thebracket-members 25, for

operates, in the formation of stitches, with suitrotation about an axistransverse to the line of 50 able loop-taker mechanism (not shown)disposed feed, is a roller 26 journaled upon an eccentric below thecloth-plate. portion 2i of a shouldered spindle or bolt 28 ro- The workto be stitched is intermittently adtatably adjustable in suitableapertures provided vanced across the cloth-plate l byafeeding mechin thebracket-members 25 and clamped in set anism of the lower four-motiontype and inposition by a nut 29. The roller supporting spindle 28 ispreferably set so that, normally, the roller 26 is barely in contactwith the rear face of the presser-bar l2, it being obvious of coursethat the roller may be adjusted relatively to the presser-bar by turningthe spindle 28.

At slow speeds of operation of the sewing machine, the presser-barspring I! effectively acts to lower the presser-foot ll upon thethroatplate 2, with the work-disengaging movement of the feed-dog 9 andbefore the feed-dog again en gages the work in a succeedingwork-advancing movement thereof. However, at higher speeds of operationof the machine, the friction between the presser-bar and its bearing orbearings is so materially increased by the thrust of the feeddog in itsaction to advance the work, that the spring I! cannot function tocompletely lower the presser-foot between consecutive work-disengagingand work-engaging movements-of the feed-dog. -In this connection, it isto be borne in mind that there are limits to the pressure which may beexerted, without detriment, by presserbar springs and particularly withcertain classes of work. However, the roller 26 constitutes antifrictionmeans absorbing excessive lateral thrusts imparted to the presser-bar,thereby relieving the presser-bar bearing from excessive friction.

In the modification of the improvement illustrated in Figs. 4 and 5 ofthe drawing, there is provided a bow-spring 30, of which the upper endengages the rear outer face of the bracket-arm head 3 above thelifter-arm 2| and the suitably rounded lower end engages the rear faceof the presser-bar below the bearing busrnng [3. The bow-spring 30 isadjustably tensioned by a screw 3| threaded into the head 3, wherebysaid spring yieldingly engages the presser-bar l2 with sulficientpressure and in a suitable direction to counteract excessivebearing-friction inducing thrusts of the feed-dog upon the presser-bar.The spring 30 is provided with a slot 32 affording clearance formovement of the hand lifter-lever 22 and the lifter-arm 2!.

In another modification illustrated in Figs. 6 and 7 of the drawing asplit collar 33 is clamped upon the portion of the bushing 13 below thehead 3, said collar having a rearwardly extending and flat-sided ear 34.The ear 34 carries a fulcrum-pin 35 projecting from the oppositeflatsides of said ear in a direction transverse to the direction offeed. Pivotally hung upon the opposite ends of said fulcrum pin todepend therefrom in parallel relation are a pair of spaced arms 36carrying a spindle or bolt 3'! upon which is journaled a roller 38disposed between said arms 36. The spindle 31 preferably correspondswith the spindle 28 illustrated more particularly in Fig. 2 of thedrawing, in that it likewise has an eccentric portion for adjustablysupporting the roller 38 and is secured in set positions by a nut 39;Engaging the rearward faces of the arms 35, are the spaced members 40 ofa forked bowspring 4 I, of which the opposite end bears against therearward face of the head 3. A screw 42 threaded into said head 3 servesto suitably tension the spring 4! to counteract the excessivefriction-inducing tendency between the presserbar and its bearings athigh speeds of operation of the machine. It will be understood that themodification illustrated in Figs. 6 and 7 of the drawing constitutes acombination of the antifriction thrust-absorbing means of Figs. 1 to 3of the drawing and the yielding thrust-absorb ing means of Figs. 4 and 5of the drawin posed to' work-engaging movements of said feeddog, apresser-foot carrying bar, a presser-bar bearing providing for endwisesliding movements of the presser-bar thereupon, and thrust-absorbingmeans opposing lateral thrust of the presserbar upon the rear wall ofsaid bearing in the direction of feed.

3. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a four-motionfeed-dog, a presser-foot yieldingly opposed to work-engaging movementsof said feed-dog, a presser-foot carrying bar, a presser-bar bearing,and anti-friction means opposing lateral thrust of the presser-bar uponsaid bearing.

4. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a fourmotionfeed-dog, a presser-foot yieldingly opposed to work-engaging movementsof said feed-dog,

a presser-foot carrying bar, a presser-bar bearing,

and yielding thrust-absorbing means opposing lateral thrust of thepresser-bar upon said bearing.

5. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a fourmotionfeed-dog, a presser-foot yieldingly opposed to work-engaging movementsof said feeddog, a presser-foot carrying bar, a presser-bar bearingproviding for endwise sliding movements of the presser-bar thereupon,and thrust-absorbing means carried by said bearing opposing lateralthrust of the presser-bar upon said bearing.

6. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a four-motionfeed-dog, a presser-foot yieldingly opposed to work-engaging movementsof said feed-dog, a presser-foot carrying bar, a presser-bar bearingproviding for endwise sliding movements of the presser-bar thereupon,and means disposed for engagement with said presser-bar between saidbearing and presser-foot and acting to oppose lateral thrust of thepresser-bar upon said bearing.

7. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a four-motionfeed-dog, a presser-foot yieldingly opposed to work-engaging movementsof said feed-dog, a presser-foot carrying bar, a presser-bar bearingproviding for endwise sliding movements of the presser-bar thereupon,and a roller supported for bodily adjustment in a direction opposed tothe direction of feed and into ment by said presser-bar.

8. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a four-motionfeed-dog, a presser-foot yieldingly opposed to position for engage-'work-engaging movements of said feed-dog, a presser-foot carrying bar, apresser-bar bearing providing for endwise sliding movements of thepresser-bar thereupon, anti-friction thrust-absorbing means, and springmeans yieldingly urging said thrust-absorbing means into engagement withsaid presser-bar.

9. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a four-motionfeed-dog, a presser-foot yieldingly, opposed to work-engaging movementsof said feed-dog, a presser-foot carrying bar, a tubular bearing inwhich said presser-bar is journaled for endwise movement, a bracketcarried by said bearing, and a thrust-absorbing roller journaled uponsaid bracket for engagement by said presser-bar to thereby opposelateral thrust of the presser-bar upon said bearing.

10. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a four-motionfeed-dog, a presser-foot yieldingly opposed to Work-engaging movementsof said feed-dog, a presser-foot carrying bar, a tubular bearing inwhich said presser-bar is journaled for endwise movement, a bracketcarried by said bearing, a thrust-absorbing roller journaled upon saidbracket for engagement by said presser-bar to thereby oppose lateralthrust of the presser-bar upon said bearing, and means providing forbodily adjustment of said roller relatively to said presser-bar.

11. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a fourmotionfeed-dog, a presser-foot yieldingly opposed to work-engaging movementsof said feeddog, a presser-ioot carrying bar, a presser-bar bearingproviding for endwise sliding movements of the presser-bar thereupon, aroller journaled for engagement with said presser-bar in a directionopposed to the direction of feed, pivotal supporting means for saidroller, and. spring means acting upon said supporting means toyieldingly hold said roller in engagement with said presser-bar tothereby oppose lateral thrust of the presser-bar upon said bearing underthe action of said feed-dog.

12. In a sewing machine, stitch-forming mechanism, a work-support, meansfor advancing work upon said work-support including a fourmotionfeeddog, a presser-foot yieldingly opposed to work-engaging movements ofsaid feeddog, a presser-foot carrying bar a presser-bar bearing, aspring tensionally opposing lateral thrust of said presser-bar upon saidbearing in the direction of feed, and means for adjusting the tension ofsaid spring.

GEORGE A. FLECKENSTEIN.

